NR AREK
AU Hirschberger,T.; Bertsch,U.; Winklhofer,K.F.; Tatzelt,J.; Kretzschmar,H.A.; Tavan,P.; Giese,A.
TI Structure-Activity Relationships of N'-Benzylidene-Benzohydrazides as Anti-Prion Drugs
QU TSE-Forum, 4. Kongress - Nationale TSE-Forschungsplattform, Düsseldorf 28.10.-29.10.2004, Poster GL-19
PT Konferenz-Poster
AB
The substance class of N'-Benzylidene-Benzohydrazide (NBB) and its structural derivatives was recently identified to show anti-prion activity both in vitro and in vivo. The active NBB compounds were selected by a multi-stage approach, whose first step was the high-throughput screening (HTS) of a diverse library containing 10.000 compounds. The HTS step was based on the SIFT-technique (Scanning for Intensely Fluorescent Targets) capable of monitoring seeded protein aggregation characteristic for scrapie prion growth. The HTS assigned anti-prion activity values to each of the tested library compounds based on their inhibitory effect on the aggregation of the cellular isoform to the scrapie prion protein. The 256 most active compounds were then re-analyzed in dilution series using the same assay, resulting in a reduced number of confirmed hits (80) characterized by in vitro EC50 values. Subsequently the confirmed in vitro hits were analyzed in vivo, in a cell culture model of prion diseases. Six of these compounds showed a significant inhibitory effect on prion propagation in vivo. Strikingly, four of the in vivo hits share the NBB core motif.
Here, we show the results of the subsequent analysis of the collected screening data. Our Structure-Activity Relationship (SAR) studies connect the molecular structure of 413 NBB compounds from the screened library to their anti-prion activities and thus serve to discover structural motifs responsible for activity. First, we applied a systematic substructure mining algorithm which constructs structural subclasses all containing the NBB core motif. Next, we have extended this approach by sorting the numerous structural classes into a hierarchy of nested subsets. This hierarchy facilitates the exploration of the information contained in the screening data. The examination of compound classes and their class local activity distributions yielded structural motifs of interest, corresponding to anti-prion activity or in-activity. In addition the procedure identifies motifs so far lacking in the library.
These SAR studies have guided the selection of new compounds for a smaller, more specialized combinatorial library around our NBB lead structure in a recently initiated follow-up project.
AD Thomas Hirschberger, Paul Tavan, Theoretische Biophysik, Lehrstuhl für BioMolekulare Optik, Ludwig-Maximilians-Universität, München, Germany; Uwe Bertsch, Hans A. Kretzschmar, Armin Giese, Zentrum für Neuropathologie und Prionforschung, Ludwig-Maximilians-Universität, München, Germany; Konstanze Winklhofer, Jörg Tatzelt, Department of Cellular Biochemistry, Max-Planck-Institute for Biochemistry, Martinsried, Germany
SP englisch
PO Deutschland
OR Tagungsband